Even on a new, high performance, computer, the graphics hardware driver could be an early 'beta' version (particularly true on new hardware designs.)

Try the diagnostic test described under 'PC Note' at the bottom of the page: http://sketchup.google.com/support/bin/answer.py?answer=36252

If the results evince that it's a graphics driver problem, do indeed obtain an updated driver. Many new machines ship with older drivers. Check the Lenovo website for any updated drivers. The general recommendation is that you always check for new drivers upon obtaining a new computer, accessories or hardware.

Regards, Taff